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1
Koromilas, Ioannis. „Performance analysis of the link-16/JTIDS waveform with concatenated coding“. Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FKoromilas.pdf.
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Thesis (M.S. in Electronic Warfare Systems Engineering)--Naval Postgraduate School, September 2009.Thesis Advisor(s): Robertson, Ralph C. "September 2009." Description based on title screen as viewed on 5 November 2009. Author(s) subject terms: Link-16/JTIDS, Reed-Solomon (RS) coding, Cyclic Code-Shift Keying (CCSK), Minimum-Shift Keying (MSK), convolutional codes, concatenated codes, perfect side information (PSI), Pulsed-Noise Interference (PNI), Additive White Gaussian Noise (AWGN), coherent detection, noncoherent detection. Includes bibliographical references (p. 79). Also available in print.
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Kagioglidis, Ioannis. „Performance analysis of a LINK-16/JTIDS compatible waveform with noncoherent detection, diversity and side information“. Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FKagioglidis%5FECE.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 2009.Thesis Advisor(s): Robertson, R. Clark. "September 2009." Description based on title screen as viewed on 6 November 2009. Author(s) subject terms: Link-16/JTIDS, (31, 15) Reed-Solomon (RS) coding, 32-ary Orthogonal signaling, Additive White Gaussian Noise (AWGN), Pulse-Noise Interference (PNI), Perfect Side Information (PSI). Includes bibliographical references (p. 49-51). Also available in print.
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Bayley, Gwain. „PC-based bit error rate analyser for a 2 Mbps data link“. Thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/23153.
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4
Fairhurst, Godred. „A study of error control techniques and the use of an enhanced X.25 LAPB protocol on a pseudo-random frequency-hopped anti-jam satellite link“. Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=129205.
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The Skynet IV satellite will provide a medium for an integrated digital communications network. This will use the packet-oriented techniques employed in many modern communications systems. One important role of the system will be to provide jam-resistant services. The advent of sophisticated electronic jammers has required the application of complex error-correcting codes and data interleaving techniques. When the satellite link forms part of a wider network, these have profound effects upon the performance of the data link protocol. This project has examined some of these effects. Terrestrial data link control protocols were found to be very inefficient, and a number of enhancements to these protocols have been proposed. An implementation of the enhanced protocols has been tested within a simulation environment. The simulator was written in Simula, an object-oriented programming language. The performance of the link was observed to be highly dependent upon the error environment presented by the underlying physical layer service (in this case a frequency-hopped spread spectrum anti-jam satellite circuit). A model of the physical layer was combined with a link layer simulator. The model used an unusual technique to reduce the computational requirements of the simulator. The project revealed that a conventional anti-jam satellite circuit is unsuitable for carriage of packetised data services. However, a number of simple changes to the protocol and error control techniques may yield a significant increase in the performance, permitting use of the service even in the harsh error environments presented by hostile jammers. These results are to be used in the specification of future satellite modems.
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Horský, Tomáš. „Rozšíření optického vláknového přenosového systému“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442378.
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The diploma thesis describes the elaboration of a program for the simulation of an optical transmission path. The work introduces the basic parameters of optical transmission, such as attenuation, dispersion and bandwidth. Furthermore, the techniques of line code and error detection are described in the work, especially a cyclic redundancy sum. The key parameter of this thesis is dispersion of the optical signal. The work includes the characteristics of the eye diagram and its analysis. The resulting program can also be used to measure the real transmission route and its parameters.
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Abdulwahid, Khalid. „Optimal decoding for line codes“. Thesis, University of Essex, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253980.
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Rutherford, Carrie Grace. „Matroids, codes and their polynomial links“. Thesis, Queen Mary, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271434.
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Mhamdi, Maroua. „Méthodes de transmission d'images optimisées utilisant des techniques de communication numériques avancées pour les systèmes multi-antennes“. Thesis, Poitiers, 2017. http://www.theses.fr/2017POIT2281/document.
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Cette thèse est consacrée à l'amélioration des performances de codage/décodage de systèmes de transmission d'images fixes sur des canaux bruités et réalistes. Nous proposons, à cet effet, le développement de méthodes de transmission d'images optimisées en se focalisant sur les deux couches application et physique des réseaux sans fil. Au niveau de la couche application et afin d'assurer une bonne qualité de service, on utilise des algorithmes de compression efficaces permettant au récepteur de reconstruire l'image avec un maximum de fidélité (JPEG2000 et JPWL). Afin d'assurer une transmission sur des canaux sans fil avec un minimum de TEB à la réception, des techniques de transmission, de codage et de modulation avancées sont utilisées au niveau de la couche physique (système MIMO-OFDM, modulation adaptative, CCE, etc). Dans un premier temps, nous proposons un système de transmission robuste d'images codées JPWL intégrant un schéma de décodage conjoint source-canal basé sur des techniques de décodage à entrées pondérées. On considère, ensuite, l'optimisation d'une chaîne de transmission d'images sur un canal MIMO-OFDM sans fil réaliste. La stratégie de transmission d'images optimisée s'appuie sur des techniques de décodage à entrées pondérées et une approche d'adaptation de lien. Ainsi, le schéma de transmission proposé offre la possibilité de mettre en oeuvre conjointement de l'UEP, de l'UPA, de la modulation adaptative, du codage de source adaptatif et de décodage conjoint pour améliorer la qualité de l'image à la réception. Dans une seconde partie, nous proposons un système robuste de transmission de flux progressifs basé sur le principe de turbo décodage itératif de codes concaténés offrant une stratégie de protection inégale de données. Ainsi, l'originalité de cette étude consiste à proposer des solutions performantes d'optimisation globale d'une chaîne de communication numérique pour améliorer la qualité de transmissionThis work is devoted to improve the coding/ decoding performance of a transmission scheme over noisy and realistic channels. For this purpose, we propose the development of optimized image transmission methods by focusing on both application and physical layers of wireless networks. In order to ensure a better quality of services, efficient compression algorithms (JPEG2000 and JPWL) are used in terms of the application layer enabling the receiver to reconstruct the images with maximum fidelity. Furthermore, to insure a transmission on wireless channels with a minimum BER at reception, some transmission, coding and advanced modulation techniques are used in the physical layer (MIMO-OFDM system, adaptive modulation, FEC, etc). First, we propose a robust transmission system of JPWL encoded images integrating a joint source-channel decoding scheme based on soft input decoding techniques. Next, the optimization of an image transmission scheme on a realistic MIMO-OFDM channel is considered. The optimized image transmission strategy is based on soft input decoding techniques and a link adaptation approach. The proposed transmission scheme offers the possibility of jointly implementing, UEP, UPA, adaptive modulation, adaptive source coding and joint decoding strategies, in order to improve the image visual quality at the reception. Then, we propose a robust transmission system for embedded bit streams based on concatenated block coding mechanism offering an unequal error protection strategy. Thus, the novelty of this study consists in proposing efficient solutions for the global optimization of wireless communication system to improve transmission quality
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Bockelmann, Carsten [Verfasser]. „Robust Link Adaptation in Coded OFDM Systems / Carsten Bockelmann“. Aachen : Shaker, 2012. http://d-nb.info/106904671X/34.
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Matrakidis, Chris. „Error control coding for constrained channels“. Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324963.
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HIROMOTO, MARIA Y. K. „PSINCO-um programa para calculo da distribuicao de potencia e supervisao do nucleo de reatores nucleares, utilizando sinais de detetores tipo 'SPD'“. reponame:Repositório Institucional do IPEN, 1998. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10706.
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Made available in DSpace on 2014-10-09T12:43:12Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:56:31Z (GMT). No. of bitstreams: 1 06442.pdf: 6689802 bytes, checksum: 46ba1e2b896e77a4288d24e80ac804ff (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Czernin, Martin. „Das Breviarium Monasticum Codex 290 (183) der OÖ. Landesbibliothek in Linz“. Tutzing Schneider, 1992. http://deposit.ddb.de/cgi-bin/dokserv?id=2801086&prov=M&dok_var=1&dok_ext=htm.
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McKown, Kenneth J. „Implementation of a fiber-optic code-division multiple access data link“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA303225.
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Kumwenda, Khumbo. „Codes, graphs and designs related to iterated line graphs of complete graphs“. Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1742_1320645699.
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In this thesis, we describe linear codes over prime fields obtained from incidence designs of iterated line graphs of complete graphs Li(Kn) where i = 1, 2. In the binary case, results are extended to codes from neighbourhood designs of the line graphs Li+1(Kn) using certain elementary relations. Codes from incidence designs of complete graphs, Kn, and neighbourhood designs of their line graphs, L1(Kn) (the so-called triangular graphs), have been considered elsewhere by others. We consider codes from incidence designs of L1(Kn) and L2(Kn), and neighbourhood designs of L2(Kn) and L3(Kn). In each case, basic parameters of the codes are determined. Further, we introduce a family of vertex-transitive graphs ôn that are embeddable into the strong product L1(Kn) â K2, of triangular graphs and K2, a class which at first sight may seem unnatural but, on closer look, is a repository of graphs rich with combinatorial structures. For instance, unlike most regular graphs considered here and elsewhere that only come with incidence and neighbourhood designs, ôn also has what we have termed as 6-cycle designs. These are designs in which the point set contains vertices of the graph and every block contains vertices of a 6-cycle in the graph. Also, binary codes from incidence matrices of these graphs have other minimum words in addition to incidence vectors of the blocks. In addition, these graphs have induced subgraphs isomorphic to the family Hn of complete porcupines (see Definition 4.11). We describe codes from incidence matrices of ôn and Hn and determine their parameters.
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Petkov, Georgy Penchev. „A unified approach to the analysis and design of digital line codes“. Thesis, City University London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332860.
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Quinn, Ciara. „Lonely cores : molecular line observations of isolated star formation“. Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/57749/.
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In this thesis, I present molecular line & continuum data of a sample of small, southern, isolated cores. I present a multi-wavelength view of the cores, by utilising optical images, 2MASS extinction maps, CO integrated intensity maps and 1.2mm continuum images of each of the cores. Spitzer data are used to identify young stellar objects local to each core, which may influence the evolution of the core. Column densities and masses are calculated for each core. The column densities calculated from the CO and 1.2mm continuum tracers are shown to be in excellent agreement with each other, and with the peak extinction, as seen on the 2MASS extinction maps. A comparison of column density derived from 1.2mm continuum and C18O observations suggest that a fraction of the gas has frozen out onto the dust grains in the densest parts of the core. The masses derived from 13CO, C18O and 1.2mm continuum observations are compared with the virial mass calculated from the observed linewidths. The cores are found to be within 3� of virial equilibrium in all cases, which suggests that all cores may be gravitationally bound. I find that the observed linewidths of the isolated cores are consistent with models of star formation by turbulent dissipation. The C18O linewidth is observed to be narrower than the 13CO linewidth, which is narrower than the 12CO linewidth in all cases. This suggests that as the density of the tracer increases, the linewidth decreases. Therefore, turbulent support against collapse is removed from the inside out, resulting in stars forming in the densest parts of the cores. I also present a proposed evolutionary diagram, based on the observed 12CO and ratio of 12CO/C18O linewidths. I hypothesise that a young core will have large 12CO and C18O linewidths. In an older core, the turbulence will have had time to dissipate in the core centre, and so the C18O linewidth will be narrower. For the oldest cores, the dissipation of turbulence will have occurred in the outer parts of the core and so the 12CO/C18O ratio will be small, indicating a more evolved core.
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Xu, Zhiyu. „Blind and group-blind multiuser detectors for reverse link in DS-CDMA systems /“. View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202002%20XU.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 111-117). Also available in electronic version. Access restricted to campus users.
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Dan, Wu. „Improvement for LDPC Coded OFDM Communication System over Power Line“. Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-128177.
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Power line communication has been around in past decades and gained renewed attention thanks to the demand of high-speed Internet access. With the significant advantages of existing infrastructure and accessibility to even remote areas, power grid has become one of the promising competitors for multi-media transmission in household. However, the power line was not oriented for data transmission providing a rather hash environment. To overcome the difficulties, advanced modulation and channel coding schemes should be employed. In the thesis low density parity check code (LDPC) is employed to reduce the loss caused by various kinds of effects in the channel especially the noise since its performance approaches to Shannon capacity limit. Moreover, OFDM multi-carrier transmission technique is involved which could decrease the inter-symbol interference and frequency selective fading. Nevertheless, LDPC decoding process was designed specifically for the common Gaussian white noise condition, combined with OFDM modulation the system still could not provide satisfying and practicable performance so improvements are needed for the system. The main works of the thesis are as follows. Set up an environment of power line transmission investigating and simulating the channel characteristics; employ multi-path channel model and Class‐A noise model for further developing the improvement algorithms to deal with the selective fading and impulse noise. Two algorithms proposed here are from different perspectives: the first one is modifying initial posterior information for LDPC decoding and the second one aims at suppressing the impulse noise after demodulation. Finally, a few simulations are performed to reveal the effectiveness of proposed methods. As a result, the improved scheme shows a great superiority improving the performance by no less than 5dB compared to traditional system.
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Scholz, Jason B. „Real-time performance estimation and optimizaton of digital communication links /“. Title page, contents and abstract only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phs368.pdf.
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Oza, Maulik D. „Performance Analysis of Turbo Coded Waveforms and Link Budget Analysis (LBA) based Range Estimation over Terrain Blockage“. University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1278524750.
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Lampow-Maundy, Helen Ann. „The design and analysis of a frame alignment algorithm applicable to guided scrambling line codes“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ31600.pdf.
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Leathers, Jane M. „CRACKING THE LINZ CIRCLE'S SECRET CODES: A SINGER'S GUIDE TO ALTERNATE INTERPRETATIONS OF SCHUBERT LIEDER“. Bowling Green State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1151698767.
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Czernin, Martin. „Das Breviarium Monasticum Codex 290 (183) der Oö. Landesbibliothek in Linz /“. Tutzing : H. Schneider, 2006. http://catalogue.bnf.fr/ark:/12148/cb41386921p.
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Texte remanié de: Dissertation--Wien, 1993. Titre de soutenance : Das Breviarium Monasticum Codex 290 (183) der Bundesstaatlichen Studienbibliothek in Linz. Eine quellenkritische Untersuchung des ältesten erhaltenen Brevieres aus dem Benediktinerstift Kremsmünster.Bibliogr. p. 479-498.
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Namburu, Visala. „Speech Coder using Line Spectral Frequencies of Cascaded Second Order Predictors“. Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/35670.
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A major objective in speech coding is to represent speech with as few bits as possible. Usual transmission parameters include auto regressive parameters, pitch parameters, excitation signals and excitation gains. The pitch predictor makes these coders sensitive to channel errors. Aiming for robustness to channel errors, we do not use pitch prediction and compensate for its lack with a better representation of the excitation signal. We propose a new speech coding approach, Vector Sum Excited Cascaded Linear Prediction (VSECLP), based on code excited linear prediction.
We implement forward linear prediction using five cascaded second order sections - parameterized in terms of line spectral frequency - in place of the conventional tenth order filter. The line spectral frequency parameters estimated by the Direct Line Spectral Frequency (DLSF) adaptation algorithm are closer to the true values than those estimated by the Cascaded Recursive Least Squares - Subsection algorithm. A simplified version of DLSF is proposed to further reduce computational complexity.
Split vector quantization is used to quantize the line spectral frequency parameters and vector sum codebooks to quantize the excitation signals. The effect on reconstructed speech quality and transmission rate, of an increased number of bits and differently split combinations, is analyzed by testing VSECLP on the TIMIT database. The quantization of the excitation vectors using the discrete cosine transform resulted in segmental signal to noise ratio of 4 dB at 20.95 kbps, whereas the same quality was obtained at 9.6 kbps using vector sum codebooks.Master of Science
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Palmé, Michael, und Felix Toppar. „Line of Code Software Metrics Applied to Novice Software Engineers“. Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264120.
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In the world of modern software engineering, there are certain metrics used to measure size and effort of projects. This provides insight to how engineers work, however when it comes to novice engineers there is little to no documentation. Without enough documentation this becomes a problem when trying to make predictions on projects involving novice software engineers, since there simply is not enough previous work on the area involving novice software engineers.The problem is that there is very little research available when it comes to how novice software engineers efficiency compares to more experienced software engineers. This makes it difficult to calculate predictions on software projects where novice engineers are involved. So how do novice engineers distribute their time and effort in a software development project?The purpose is to find out how the time is distributed in a workplace involving novice software engineers. Further is to learn more of the differences between how novice and experienced software engineers distribute their time and effort in a project.The goal of this thesis is to improve the understanding of how novice software engineers contribute to a software project.In this work, a case study has been done with two novice engineers at a workplace in order to learn more about how novice engineers contribute to a software project. In this case study, a quantitative research method was adapted using the Line of Code software metric to document how the novice engineers distributed their time.The results of the case study showed that the two novice engineers spent far more time coding than planning and that they wrote code faster than the average experienced engineer.Menigen med detta arbete är att ta reda på hur tiden som läggs på ett mjukvaruprojekt distrubieras på en arbetsplats med nyutbildade mjukvaruingenjörer.Målet med detta arbete är att förbättra förståelsen angående hur nyutbildade mjukvaruingenjörer bidrar till ett mjukvaruprojekt.I det här arbetet så har en fallstudie gjorts med två stycken nyutbildade mjukvaruingenjörer för att undersöka hur nyutbildade ingenjörer bidrar till ett mjukvaruprojekt. Fallstudien följer dessa två ingenjörer på en arbetsplats där en kvantitativ undersökning görs med hjälp av Line of Code mjukvarumetriken som används för att dokumentera hur ingenjörerna fördelade sin tid på arbetsplatsen.Resultaten av fallstudien visade att dessa två nyutbildade ingenjörer spenderade mycket mer tid åt kodande än åt planerande, och att de skrev kod snabbare än den genomsnittliga erfarna ingenjören.
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Rahmatdoustbeilankouh, Bahram. „Communication link and code conversion between Vehicle and smartphone for low speed semi-autonomous maneuvering“. Thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-26588.
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Something that has recently gained popularity in the leading car manufacturing companies is the integration of an auto-reverse assistance system to improve the customer experience. The undeniable spread of smartphones and their significant role in human life in recent years, gave rise to the idea of designing an application to be used for reverse driving. As a result, the car company Volvo proposed an idea for this project: to implement an Android based application to facilitate reverse navigation in their trucks. From a technical point of view, the most crucial obstacle that should be addressed is implementing a secure and reliable communication link between the smartphone and the truck's control centre. Hence, the primary goal of this thesis work is to provide a secure channel to transmit data and computing reliability of the com-munication link. Another objective of this project is to define a solution for auto-converting path plan function, currently developed in Matlab, to run on Android devices. In addition, this solution should enable the developer to modify the path plan function in Matlab without having to consider Android programming. The differential method has been proposed for transferring secure data transfer using Bluetooth technol-ogy. This solution not only increases the security of the communication link but also improves transmission time. Another objective has been reached by developing a middleware function using C programming language and Android Native Development Kite (NDK) between An-droid and Matlab. The result of these solutions provides a reliable communication link and runs the developed path plan function in Android phone.
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Maamar, Ali Hussein. „A 32-bit self-checking RISC processor using Dong's Code“. Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285335.
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Luna, Ricardo, und Hrishikesh Tapse. „An Analysis on the Coverage Distance of LDPC-Coded Free-Space Optical Links“. International Foundation for Telemetering, 2008. http://hdl.handle.net/10150/606240.
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ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, CaliforniaWe design irregular Low-Density Parity-Check (LDPC) codes for free-space optical (FSO) channels for different transmitter-receiver link distances and analyze the error performance for different atmospheric conditions. The design considers atmospheric absorption, laser beam divergence, and random intensity fluctuations due to atmospheric turbulence. It is found that, for the same transmit power, a system using the designed codes works over much longer link distances than a system that employs regular LDPC codes. Our analysis is particularly useful for portable optical transceivers and mobile links.
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Ren, Manling. „Algorithms for off-line recognition of Chinese characters“. Thesis, Nottingham Trent University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245175.
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Ning, Baozhu. „Performance Analysis of Iterative Soft Interference Cancellation Algorithms and New Link Adaptation Strategies for Coded MIMO Systems“. Thesis, Supélec, 2013. http://www.theses.fr/2013SUPL0034/document.
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Les systèmes de communication sans fil actuels évoluent vers un renforcement des réactivités des protocles de la gestion des ressources radio (RRM) et adaptation du lien radipe (FLA) afin d'optimiser conjointement les couches MAC et PHY. En parallèle, la technologie d'antenne multiples et turbo récepteurs avancés ont un grand potentiel pour augmenter l’efficacité spectrale dans les futurs systèmes de communication sans fil. Ces deux tendances, à savoir, l'optimisation inter couche et le traitement de turbo, nécessitent le développement de nouvelles abstractions de la couche PHY (aussi appelée méthode de prédiction de la performance) qui peuvent capturer les performances du récepteur itératif par itération pour permettre l'introduction en douceur de ces récepteurs avancés dans FLA et RRM.La thèse de doctorat revisite en détail l'architecture du turbo récepteur, plus particulièrement, la classe d'algorithme itératif effectuant la détection linéaire par minimisation d’erreur quadratique moyenne avec l'annulation d’interférence (LMMSE-IC). Ensuite, une méthode semi-analytique de prédiction de la performance est proposée pour analyser son l'évolution par la modélisation stochastique de chacun des composants. Intrinsèquement, la méthode de prédiction de la performance est subordonnée à la disposition de connaissance d’information d’état du canal au niveau du récepteur (CSIR), le type de codage de canal (code convolutif ou un code turbo), le nombre de mots de code ainsi que le type d’information probabilistic sur les bits codés réinjectée par le décodeur pour la reconstruction et l'annulation d'interférence à l'intérieur d’algorithme de LMMSE -IC itératif.Dans la deuxième partie, l’adaptation du lien en boucle fermée dans les systèmes MIMO codés basés sur les abstractions de la couche PHY proposées pour les récepteurs LMMSE -IC itératifs ont été abordés. Le schéma proposé d'adaptation de liaison repose sur un faible taux de rétroaction et exploite la sélection du précodeur spatiale (par exemple, la sélection d'antennes) et du schéma de modulation et de codage (MCS) de façon à maximiser le taux moyen soumis à une contrainte de taux d'erreur de bloc. Différents schémas de codage sont testés, tels qu’un codage parcourant tous les antennes où un codage par antenne. Les simulations montrent bien le gain important obtenu avec les turbo récepteurs comparée à celui d’un récepteur MMSE classiqueCurrent wireless communication systems evolve toward an enhanced reactivity of Radio Resource Management (RRM) and Fast Link Adaptation (FLA) protocols in order to jointly optimize the Media Access Control (MAC) and Physical (PHY) layers. In parallel, multiple antenna technology and advanced turbo receivers have a large potential to increase the spectral efficiency of future wireless communication system. These two trends, namely, cross layer optimization and turbo processing, call for the development of new PHY-layer abstractions (also called performance prediction method) that can capture the iterative receiver performance per iteration to enable the smooth introduction of such advanced receivers within FLA and RRM. The PhD thesis first revisits in detail the architecture of the turbo receiver, more particularly, the class of iterative Linear Minimum Mean-Square Error (soft) Interference Cancellation (LMMSE-IC) algorithms. Then, a semi-analytical performance prediction method is proposed to analyze its evolution through the stochastic modeling of each of the components. Intrinsically, the performance prediction method is conditional on the available Channel State Information at Receiver (CSIR), the type of channel coding (convolutional code or turbo code), the number of codewords and the type of Log Likelihood Ratios (LLR) on coded bits fed back from the decoder for interference reconstruction and cancellation inside the iterative LMMSE-IC algorithms. In the second part, closed-loop FLA in coded MIMO systems based on the proposed PHY-layer abstractions for iterative LMMSE-IC receiver have been tackled. The proposed link adaptation scheme relies on a low rate feedback and operates joint spatial precoder selection (e.g., antenna selection) and Modulation and Coding Scheme (MCS) selection so as to maximize the average rate subject to a target block error rate constraint. The cross antenna coding (the transmitter employs a Space-Time Bit-Interleaved Coded Modulation (STBICM) ) and per antenna coding (Each antenna employs an independent Bit-Interleaved Coded Modulation(BICM)) cases are both considered. The simulations clearly show the significant gain obtained with turbo receivers compared to that of a conventional MMSE receiver
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Wickberg, Fredrik. „HDL code analysis for ASICs in mobile systems“. Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9762.
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The complex work of designing new ASICs today and the increasing costs of time to market (TTM) delays are putting high responsibility on the research and development teams to make fault free designs. The main purpose of implementing a static rule checking tool in the design flow today is to find errors and bugs in the hardware definition language (HDL) code as fast and soon as possible. The sooner you find a bug in the design, the shorter the turnaround time becomes, and thereby both time and money will be saved.
There are a couple of tools in the market that performs static HDL analysis and they vary in both price and functionality. In this project mainly Atrenta Spyglass was evaluated but similar tools were also evaluated for comparison purpose.
The purpose of this master thesis was to evaluate the need of implementing a rule checking tool in the design flow at the Digital ASIC department PDU Base Station development in Kista, who also was the commissioner for this project. Based on the findings in this project it is recommended that a static rule checking tool is introduced in the design flow at the ASIC department. However, in order to determine which of the different tools the following pointers should be regarded:
• If the tool is only going to be used as for lint checks (elementary structure and code checks) on RTL, then the implementation of Mentors Design Checker is advised.
• If the tool is going to be used for more sophisticated structural checks, clock tree/reset tree propagation, code checks, basic constraints checks, basic Clock Domain Crossings (CDC) checks, then Synopsys LEDA is advised.
• If the tool is going to be used as for advanced structural checks, extensive clock tree/reset tree propagation, code checks, constraints checks, functional Design For Test (DFT) checks (as testmode signal propagation) and functional CDC checks on RTL as well as on netlist level, then Atrenta Spyglass is advised.
The areas regarding checks that could be of interest for Ericsson is believed to be regular lint checks for RTL (naming, code and basic structure), clock/reset tree propagation (netlist and RTL), constraints and functional DFT checks (netlist and RTL).
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Andre, John W. „Feasibility study of implementing a code division multiple access data link utilizing fiber optic delay lines“. Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23899.
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Franková, Anna. „MY CODE/WORLD“. Master's thesis, Vysoké učení technické v Brně. Fakulta výtvarných umění, 2017. http://www.nusl.cz/ntk/nusl-316051.
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My Code/World is a personal artistic research of the environment in which I work as a programmer - not a physical environment, but the virtual environment of a computer interface. This research has been taking place since roughly October 2016 and its result is a collection of loosely connected pieces (sketches, experiments), that will be presented as an installation within the studio space of the Studio Graphic Design 2, Faculty of Fine Arts, BUT.
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Chapman, David. „Dark signalling and code division multiple access in an optical fibre LAN with a bus topology“. Thesis, Open University, 2002. http://oro.open.ac.uk/22800/.
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This thesis describes an optical fibre network that uses a bus topology and Code Division Multiple Access (CDMA). Various potential configurations are analysed and compared and it is shown that a serious limitation of optical CDMA schemes using incoherent correlators is the effect of optical beating due to the presence of multiple incoherent optical signals at the receiver photodiode. The network proposed and analysed in this thesis avoids beating between multiple optical fields because it only uses a single, shared, optical source. It does this through the SLIM (Single Light-source with In-line Modulation) configuration in which there is a continuously-operating light source at the head-end of a folded bus, and modulators at the nodes to impose signals on the optical field in the form of pulses of darkness which propagate along the otherwise continuously bright bus. Optical CDMA can use optical-fibre delay-line correlators as matched filters, and these may be operated either coherently or incoherently.Coherent operation is significantly more complex than incoherent operation, but incoherent correlators introduce further beating even in a SLIM network. A new design of optical delay-line correlator, the hybrid correlator, is therefore proposed, analysed and demonstrated. It is shown to eliminate beating. A model of a complete network predicts that a SLIMbus using optical CDMA with hybrid correlators can be operated at TeraBaud rates with the number of simultaneous users limited by multiple access interference (MAI), determined only by the combinatorics of the code set.
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Thompson, Mark Anthony. „Hot cores and HII regions : molecular line and continuum observations of massive star formation“. Thesis, University of Kent, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298097.
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Lapinski, Richard Allen. „A case study to determine the feasibility of on-line ink jet printing of bar codes onto corrugated shipping containers /“. Online version of thesis, 1995. http://hdl.handle.net/1850/12226.
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Meißner, Christian. „Entwicklung von dynamischen Bibliotheken (DLL) für Mathcad : Effizienzsteigerung, Quellcodeschutz, Codeportierung“. Universitätsbibliothek Chemnitz, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200900826.
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Ein Vorteil von Mathcad® ist das übersichtliche Arbeitsblatt. Mathematische Gleichungen werden nicht als verwirrende Kette von Buchstaben und Zahlen dargestellt, sondern in eindeutiger mathematischer Notation. Die Gleichungen werden standardmäßig nach der Eingabe auf Plausibilität geprüft. Viele Funktionen - auch komplexe Lösungsalgorithmen - werden bereits mitgeliefert. Weiterhin können formatierte Textfelder für eine gute Dokumentation genutzt werden, z.B. für Berechnungsnachweise. Daher kann das Arbeitsblatt in sehr kurzer Zeit entwickelt werden und ist für neue Anwender leicht nachzuvollziehen. Jedoch wird jeder Vorteil durch einen Nachteil erkauft. So liegen eine geringere Rechengeschwindigkeit, eingeschränkter Codeschutz und nur wenige Möglichkeiten zur Kommunikation mit anderen Programmen vor. Diese Nachteile können durch dynamische Bibliotheken verringert werden. Dieser Artikel stellt die Vorteile der DLL-Programmierung für Mathcad® dar und zeigt einige Beispiele zur Erhöhung der Rechengeschwindigkeit, zum Quellcodeschutz und zur CodeportierungOne advantage of Mathcad® is the well arranged worksheet. Mathematic equations are not displayed in confusing chains of characters but in clear mathematical notation. The equations normaly are checked of plausibility including units after writing. Many functions - even complex solving algorithms - are already defined. Furthermore formatted comments lead to a good documentation, e.g. for calculation reports. Hence the calculation sheets are developed in a very short time and they are easy to comprehend for new users. However every advantage is bought by a disadvantage. Therefore there is a less calculation speed, limited possibilities for code protection and only few possibilities of communication with other programs. These disadvantages can be removed by using dynamic link libraries (DLL's). This article gives an introduction of programming DLL's in Mathcad® and shows some examples to increase calculation efficiency, code protection and code transfer
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Duée, Cédric, Beate Orberger, Nicolas Maubec, Xavier Bourrat, Mendili Yassine El, Stéphanie Gascoin, Daniel Chateigner et al. „Challenges in coupled on-line-on-mine-real time mineralogical and chemical analyses on drill cores“. TU Bergakademie Freiberg, 2017. https://tubaf.qucosa.de/id/qucosa%3A23177.
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The SOLSA project aims to develop an innovative on-line-on-mine-real-time expert system, combining sonic drilling, mineralogical and chemical characterization and data treatment. Ideally, this combination, highly demanded by mining and metallurgical companies, will speed up exploration, mining and processing.
In order to evaluate the instrumental parameters for the SOLSA expert system, portable and laboratory analyses have been performed on four samples with contrasting lithologies: siliceous breccia, serpentinized harzburgite, sandstone and granite. More precisely, we evaluated the influence of the surface state of the sample on the signals obtained by portable X-Ray Fluorescence (pXRF) for chemistry and portable Infra-Red spectroscopy (pIR) for mineralogy. In addition, laboratory Raman spectroscopy, X-Ray Diffraction (XRD), XRF and ICP-OES laboratory analyses were performed to compare surface bulk mineralogical and chemical analyses.
This presentation highlights (1) the importance of coupling chemical and mineralogical analytical technologies to obtain most complete information on samples, (2) the effect of the sample surface state on the XRF and IR signals from portable instruments. The last point is crucial for combined instrumental on-line sensor design and the calibration of the different instruments, especially in the case of pXRF.
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Duée, Cédric, Beate Orberger, Nicolas Maubec, Xavier Bourrat, Mendili Yassine El, Stéphanie Gascoin, Daniel Chateigner et al. „Challenges in coupled on-line-on-mine-real time mineralogical and chemical analyses on drill cores“. Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2018. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-231144.
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The SOLSA project aims to develop an innovative on-line-on-mine-real-time expert system, combining sonic drilling, mineralogical and chemical characterization and data treatment. Ideally, this combination, highly demanded by mining and metallurgical companies, will speed up exploration, mining and processing.
In order to evaluate the instrumental parameters for the SOLSA expert system, portable and laboratory analyses have been performed on four samples with contrasting lithologies: siliceous breccia, serpentinized harzburgite, sandstone and granite. More precisely, we evaluated the influence of the surface state of the sample on the signals obtained by portable X-Ray Fluorescence (pXRF) for chemistry and portable Infra-Red spectroscopy (pIR) for mineralogy. In addition, laboratory Raman spectroscopy, X-Ray Diffraction (XRD), XRF and ICP-OES laboratory analyses were performed to compare surface bulk mineralogical and chemical analyses.
This presentation highlights (1) the importance of coupling chemical and mineralogical analytical technologies to obtain most complete information on samples, (2) the effect of the sample surface state on the XRF and IR signals from portable instruments. The last point is crucial for combined instrumental on-line sensor design and the calibration of the different instruments, especially in the case of pXRF.
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Mácha, Tomáš. „Využití nástroje MATLAB Coder pro automatické generování C kódu pro mikrokontroléry dsPIC“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-402535.
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Generating C code from MATLAB can be a powerful tool for a wide range of engineering problems. Especially in cases where MATLAB excels, including matrix operations and some of the built-in functions, code conversion may represent a significant assistance in their development. The aim of this master's thesis is to explore the possibilities of generating C code using MATLAB Coder App. As the documentation for MATLAB Coder was not found sufficient a theoretical basis for the use of this tool was introduced along with simple examples of possible applications. Next, code generation for controlling a laboratory DC motor using a microcontroller dsPIC was made automatic and controlled directly from a single MATLAB script. Individual steps were described to supplement existing documentation and to allow for an easy use. Finally, selected functions were tested for code generation. As a result, certain limitations can be outlined, as well as suitability of both the created tool and the MATLAB Coder App.
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Morozov, Alexei. „Optimierung von Fehlererkennungsschaltungen auf der Grundlage von komplementären Ergänzungen für 1-aus-3 und Berger Codes“. Phd thesis, Universität Potsdam, 2005. http://opus.kobv.de/ubp/volltexte/2005/536/.
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Die Dissertation stellt eine neue Herangehensweise an die Lösung der Aufgabe der funktionalen Diagnostik digitaler Systeme vor. In dieser Arbeit wird eine neue Methode für die Fehlererkennung vorgeschlagen, basierend auf der Logischen Ergänzung und der Verwendung von Berger-Codes und dem 1-aus-3 Code. Die neue Fehlererkennungsmethode der Logischen Ergänzung gestattet einen hohen Optimierungsgrad der benötigten Realisationsfläche der konstruierten Fehlererkennungsschaltungen. Außerdem ist eins der wichtigen in dieser Dissertation gelösten Probleme die Synthese vollständig selbstprüfender Schaltungen.In this dissertation concurrent checking by use of a complementary circuit for an 1-out-of-n Codes and Berger-Code is investigated. For an arbitrarily given combinational circuit necessary and sufficient conditions for the existence of a totally self-checking checker are derived for the first time.
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Nascimento, Leandro Marques do. „Cores assets development in software product lines - towards a practical approach for the mobile game domain“. Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/1683.
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Previous issue date: 2008Os mais almejados objetivos da engenharia de software são basicamente alta produtividade, com alta qualidade a um baixo custo e uma possível forma de atingi-los é estabelecer reuso de software o processo de criar sistemas de software a partir de sistemas existentes ao invés de criar do início. Neste contexto, uma abordagem que pode habilitar reuso na prática é Linha de Produto de Software (LPS) um conjunto de sistemas de software que compartilham um conjunto comum e gerenciado de funcionalidades que satisfazem uma necessidade específica de um domínio, e que são desenvolvidas a partir de um conjunto de artefatos reusáveis. Um domínio em particular onde a adoção de tal abordagem pode trazer benefícios é o domínio de jogos móveis principalmente porque os jogos precisam executar em diversos dispositivos e existe uma grande quantidade de jogos do mesmo tipo sendo desenvolvidos com funcionalidades em comum. Entretanto, as características do domínio de jogos móveis geralmente criam barreiras para os processos de LPS na prática, tais como, restrições de memória e de tamanho da aplicação e diferentes implementações de API feitas por diferentes fabricantes. Além disso, os atuais processos de LPS ainda carecem de detalhes em fases relacionadas à implementação de artefatos reusáveis, dificultando a administração apropriada das características mencionadas. Dessa forma, este trabalho objetiva definir uma abordagem prática para implementação de artefatos reusáveis em uma LPS para o domínio de jogos móveis com base nas boas práticas do estado da arte na área. Além disso, com a intenção de avaliar a abordagem, um estudo experimental foi executado com três jogos de plataforma para construir a LPS e um quarto jogo foi derivado dela
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Anderson, Christopher R. „Evaluation of gigabit links for use in HEP trigger processing“. Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367118.
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McLellan, James A. H. „Malay-English language alternation in two Brunei Darussalam on-line discussion forums“. Curtin University of Technology, Department of Language and Intercultural Education, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16277.
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This is a study of language choice and language alternation patterns in a corpus of messages posted on two Brunei Darussalam on-line discussion forums. It aims to break new ground by investigating Malay-English language alternation in the context of computer-mediated communication (CMC), in contrast to previous research which has mostly studied alternation or code-switching in informal conversations. The corpus of texts consists of 21 1 messages posted on the 'Bruclass' and 'Brudirect' forums. These were analysed in terms of their grammatical and discoursal features to determine what role is played by each of the contributing languages. Chapter 1 outlines the major research questions: how much alternation is there between Malay and English, how is this alternation achieved, and why do the bilingual text producers make these language choices when posting their messages in the on-line forums? This chapter also includes outline description of the sociolinguistic context of Brunei Darussalam in terms of its population, history, system of education, and discussion of the varieties of Malay and of English used by Bruneians. In Chapter 2 relevant literature on language alternation is reviewed, with a gradual narrowing of the focus: from theories of code-switching and language alternation to studies dealing specifically with Malay-English code-switching in Malaysia and in Brunei Darussalam. Studies on language use and alternation in the CMC domain are also reviewed. Chapter 3 discusses the combination of quantitative and qualitative methods, and the rationale for these. Findings from the grammatical and discoursal analyses are reported and discussed in Chapter 4. Whilst monolingual English messages are the most frequent, almost half of the corpus texts are found to include a measure of Malay-English alternation.Many of these display an asymmetric alternation pattern, in which one language supplies the grammar and the other the lexis, but there are also examples of equal alternation, where Malay and English both contribute to the grammar and to the lexis. The reasons for these choices are investigated through a questionnaire survey, which includes a text ranking task, and through other published texts in which Bruneians discuss their use of language. Chapter 5 discusses these findings, and the concluding Chapter 6 considers connections between the analysis of the texts and the questionnaire survey, especially the preference for monolingual English. Chapter 6 also includes discussion of questions of identity as reflected in the language choices and of language use in the CMC domain.
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Brabec, Martin. „Spolupráce leteckých společností“. Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-73879.
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This diploma thesis topic is cooperation among airlines. Main part focuses on areas and forms of airline cooperation e.g. inter-lining, code-sharing, joint ventures. A chapter is dedicated to the impact on competition and another one analysis the structure of global airline alliances. Basic overview of air transport and legal aspects influencing the nature of cooperation among airlines is also included.
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Piolho, Francisco de Assis Pereira. „Fases e criticalidade no modelo ashkin - teller de tr?s cores“. Universidade Federal do Rio Grande do Norte, 2007. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16544.
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Previous issue date: 2007-12-14The usual Ashkin-Teller (AT) model is obtained as a superposition of two Ising models coupled through a four-spin interaction term. In two dimension the AT model displays a line of fixed points along which the exponents vary continuously. On this line the model becomes soluble via a mapping onto the Baxter model. Such richness of multicritical behavior led Grest and Widom to introduce the N-color Ashkin-Teller model (N-AT). Those authors made an extensive analysis of the model thus introduced both in the isotropic as well as in the anisotropic cases by several analytical and computational methods. In the present work we define a more general version of the 3-color Ashkin-Teller model by introducing a 6-spin interaction term. We investigate the corresponding symmetry structure presented by our model in conjunction with an analysis of possible phase diagrams obtained by real space renormalization group techniques. The phase diagram are obtained at finite temperature in the region where the ferromagnetic behavior is predominant. Through the use of the transmissivities concepts we obtain the recursion relations in some periodical as well as aperiodic hierarchical lattices. In a first analysis we initially consider the two-color Ashkin-Teller model in order to obtain some results with could be used as a guide to our main purpose. In the anisotropic case the model was previously studied on the Wheatstone bridge by Claudionor Bezerra in his Master Degree dissertation. By using more appropriated computational resources we obtained isomorphic critical surfaces described in Bezerra's work but not properly identified. Besides, we also analyzed the isotropic version in an aperiodic hierarchical lattice, and we showed how the geometric fluctuations are affected by such aperiodicity and its consequences in the corresponding critical behavior. Those analysis were carried out by the use of appropriated definitions of transmissivities. Finally, we considered the modified 3-AT model with a 6-spin couplings. With the inclusion of such term the model becomes more attractive from the symmetry point of view. For some hierarchical lattices we derived general recursion relations in the anisotropic version of the model (3-AAT), from which case we can obtain the corresponding equations for the isotropic version (3-IAT). The 3-IAT was studied extensively in the whole region where the ferromagnetic couplings are dominant. The fixed points and the respective critical exponents were determined. By analyzing the attraction basins of such fixed points we were able to find the three-parameter phase diagram (temperature ? 4-spin coupling ? 6-spin coupling). We could identify fixed points corresponding to the universality class of Ising and 4- and 8-state Potts model. We also obtained a fixed point which seems to be a sort of reminiscence of a 6-state Potts fixed point as well as a possible indication of the existence of a Baxter line. Some unstable fixed points which do not belong to any aforementioned q-state Potts universality class was also found
O modelo Ashkin-Teller (AT) usual consiste na superposi??o de dois modelos de Ising acoplados por um termo de intera??o de quatro spins. Em duas dimens?es o modelo AT apresenta uma linha de pontos fixos com expoentes cr?ticos variando continuamente, sobre a qual ele se torna sol?vel atrav?s de um mapeamento no modelo Baxter. Motivado por esta riqueza de comportamento multicr?tico em duas dimens?es, Grest e Widom introduziram e estudaram o modelo Ashkin-Teller de N cores (AT-N), nas vers?es anisotr?pica (AAT-N) e isotr?pica (IAT-N), atrav?s de v?rios m?todos anal?ticos e computacionais. Neste trabalho apresentamos uma vers?o mais geral do modelo Ashkin-Teller de 3 cores (AT-3) onde e introduzido um acoplamento de 6 spins. Estudamos o modelo atrav?s da an?lise da estrutura de suas simetrias, seguido de an?lises de poss?veis diagramas de fases determinados por t?cnicas de grupo de renormaliza??o no espa?o real. Esses diagramas s?o obtidos em temperatura finita na regi?o onde predomina o comportamento ferromagn?tico. Com o aux?lio do conceito de transmissividade obtemos as rela??es de recorr?ncia em redes hier?rquicas com liga??es peri?dicas e quasi-peri?dicas. Numa an?lise preliminar, consideramos inicialmente o modelo Ashkin-Teller de duas cores, a fim de obter resultados que possam servir de guia ao nosso objetivo principal. No caso anisotr?pico (AAT-2), o modelo foi tratado na Ponte de Wheatstone, conforme j? havia sido estudado por Claudionor Bezerra na sua disserta??o de mestrado. Usando ferramentas computacionais mais adequadas, encontramos superf?cies cr?ticas isomorfas previstas no trabalho citado, mas ainda n?o identificadas explicitamente. Al?m disso, analisamos a vers?o isotr?pica (IAT-2), em uma rede hier?rquica aperi?dica. Mostramos,neste caso, como a aperiodicidade da rede afeta as flutua??es geom?tricas, causando mudan?as no comportamento cr?tico do modelo. Essas an?lises foram feitas utilizando defini??es apropriadas de transmissividade. Em seguida passamos ao estudo do modelo Ashkin-Teller de 3 cores onde, al?m do acoplamento de 4 spins, introduzimos um acoplamento de 6 spins, que torna o modelo mais atraente do ponto de vista das simetrias que ele passa a apresentar. Calculamos rela??es de recorr?ncias gerais para o modelo na vers?o anisotr?pica (AAT-3), de onde podemos obter o caso particular do sistema isotr?pico (IAT-3), em certas redes hier?rquicas. A vers?o IAT-3 do modelo foi estudada detalhadamente na regi?o onde predominam as intera??es ferromagn?ticas. Determinamos os pontos fixos e respectivos expoentes cr?ticos. Analisando as bacias de atra??o desses pontos fixos, conseguimos obter o diagrama de fases tri-dimensional (temperatura ? acoplamento de quatro spins ? acoplamento de seis spins). Identificamos pontos fixos do tipo Ising e de Potts de 4 e de 8 estados, al?m de ind?cios de um ponto fixo reminiscente do Potts de 6 estados e uma possibilidade de uma linha de Baxter. Identificamos tamb?m pontos fixos cr?ticos inst?veis que n?o pertencem a nenhuma classe de universalidade identificada com o modelo de Potts q estados
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Quénard, David. „Modélisation 3D de régions de formation d'étoiles : la contribution de l'interface graphique GASS aux codes de transfert radiatif“. Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30232/document.
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L'ère des observations interférométriques mène à la nécessité d'une description plus précise de la structure physique et de la dynamique des régions de formation d'étoiles, des coeurs pré-stellaires et des disques proto-planétaires. L'émission moléculaire et du continuum de la poussière peuvent être décrites par de multiples composantes physiques. Pour comparer avec les observations, un modèle de transfert radiatif précis et complexe de ces régions est nécessaire. J'ai développé au cours de cette thèse une application autonome appelée GASS (Generator of Astrophysical Sources Structures, Quénard et al., soumis) à cette fin. Grâce à son interface, GASS permet de créer, de manipuler et de mélanger différents composants physiques tels que des sources sphériques, des disques et des outflows. Dans cette thèse, j'ai utilisé GASS pour travailler sur différents cas astrophysiques et, entre autres, j'ai étudié en détail l'eau et l'émission de l'eau deutérée dans le coeur pré-stellaire L1544 (Quénard et al., 2016) ainsi que l'émission des ions dans la proto-étoile de faible masse IRAS16293-2422 (Quénard et al., soumis)The era of interferometric observations leads to the need of a more and more precise description of physical structure and dynamics of star-forming regions, from pre-stellar cores to proto-planetary disks. The molecular and dust continuum emission can be described with multiple physical components. To compare with the observations, a precise and complex radiative transfer modelling of these regions is required. I have developed during this thesis a standalone application called GASS (Generator of Astrophysical Sources Structures, Quénard et al., submitted) for this purpose. Thanks to its interface, GASS allows to create, manipulate, and mix several different physical components such as spherical sources, disks, and outflows. In this thesis, I used GASS to work on different astrophysical cases and, among them, I studied in details the water and deuterated water emission in the pre-stellar core L1544 (Quénard et al., 2016) and the emission of ions in the low-mass proto-star IRAS16293-2422 (Quénard et al., submitted)
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Aivaliotis, Theodoros. „Performance analysis of a JTIDS/link-16-type waveform using 32-ary orthogonal signaling with 32 chip baseband waveforms and a concatenated code“. Thesis, Monterey, California: Naval Postgraduate School, 2009. http://hdl.handle.net/10945/4472.
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Approved for public release, distribution unlimitedThe Joint Tactical Information Distribution System (JTIDS)) is a hybrid frequency-hopped, direct sequence spread spectrum system which used cyclic code-shift keying (CCFK) for M-ary symbol modulation and minimum shift-keying (MSK) for chip modulation. In addition JTIDS uses a (31, 15) Reed Solomon (RS) code for channel coding. In this thesis an alternative waveform consistent with the original JTIDS waveform is analyzed. The system to be considered uses a concatenated code consisting of a (31, k) Reed Solomon inner code and a 4/5 convolutional outer code. The coded symbols are transmitted on the in-phase (I) and quadrature (Q) components of the carrier using 32-ary orthogonal signaling with 32 chip basedband waveforms such as Walsh functions. Performance with both coherent and noncoherent detection is analyzed. For noncoherent detection only one five bit symbol is transmitted on the I and Q components of the carrier per symbol duration, so the data throughput for noncoherent detection 1/2 that of coherent detection. No diversity, consistent with JTIDS single-pulse structure, and a sequential diversity of two, consistent with JTIDS double-pulse structure, are both considered. For the double-pulse structure, performance is examined both for the case of linear soft diversity combining and also for soft diversity combining with perfectside information. Performance is examined for both AWGN only, as well as for AWGN and pulse-noise interference. Based on the results of this thesis, the proposed waveform is found to outperform the existing JTIDS/Link-16 waveform in all cases considered in this research. Indeed, the best performance for the atlernative waveform is obtained when an (31, 25) RD inner code is used. When only AWGN is present, the proposed waveform with no diversity has a gain of 2.6 dB and 2.5 dB as compared to the existing JTIDS/Link-16 wavefoorm for coherent and noncoherent demodulation, respectively, when Pb =10-5. Likewise in an AGWN only environment with a diversity of two, the proposed waveform outperforms the existing JTIDS/Link-16 waveform by 3.15 dB and 23 dB for coherent and noncoherent detection, respectively. When PNI is also present, the proposed waveform performs significantly better than the existing JTIDS waveform in all cases considered. Finally, the use of a concatenated code consisting of a (31, 25) RS inner code and a 4/5 convolutional outer code results in a 33% improvement in throughput as compared to the existing JTIDS/Link-16 waveform.
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Tanaka, Pedro Sena. „Algoritmos eficientes para a detecção on-line do padrão floco em bancos de dados de trajetórias“. Universidade Estadual de Londrina. Centro de Ciências Exatas. Programa de Pós-Graduação em Ciência da Computação, 2016. http://www.bibliotecadigital.uel.br/document/?code=vtls000206562.
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A alta disponibilidade, baixo custo e crescente utilização de dispositivos de localização fez aumentar o interesse por pesquisas na área de padrões espaço-temporais. O principal objetivo em estudar tais padrões é descobrir relacionamentos espaciais entre objetos móveis e entender como eles se desenvolvem ao decorrer do tempo. Trabalhos recentes da literatura propuseram uma grande variedade destes padrões, entre eles está o padrão floco. Este padrão consiste em identificar se um dado número de entidades se movimentam por um certo período de tempo próximas entre si, isto é, se encontram-se em um disco de raio predefinido em instantes subsequentes de tempo. Exemplos típicos de aplicação incluem a monitoração e vigilância uma vez que ambas dependem da identificação ágil de grupos suspeitos formados por pessoas/veículos em fluxos volumosos de dados espaço-temporais. Trabalhos da literatura propuseram algoritmos que resolvem o problema do padrão floco com tempo fixo em tempo polinomial. Nesta dissertação é proposto um novo algoritmo on-line para a detecção de flocos com tempo fixo chamado PSI, que aplica a técnica de geometria computacional varredura de plano, além das técnicas de assinaturas binárias e a estrutura índice invertido. Além do método PSI, este trabalho propõe uma família de algoritmos, todos baseados no método proposto na literatura chamado BFE. Todos estes métodos foram testados de forma extensiva utilizando conjuntos de dados reais e sintéticos e os resultados obtidos comprovam que as técnicas propostas no trabalho geram ganhos consideráveis quando aplicadas aos algoritmos de descoberta de flocos. Para melhor entender os resultados e apontar os melhores e piores cenários para a aplicação das técnicas foi feita uma análise aprofundada da relação entre os resultados e a distribuição e outras características dos dados.The high availability, low cost and increasing usage of location-aware devices have increased the interest in the research of spatiotemporal patterns. The main goal in studying such patterns is to discover spatial relationships over time between moving objects. Recent articles have proposed a wide variety of such patterns, among them is the flock pattern. This pattern is defined as a set of moving objects with minimum size that stay together within a maximum distance for a continuous period of time. Typical application examples are monitoring and surveillance that both rely on efficiently identifying groups of suspicious people/vehicles in large spatiotemporal streaming data. Previous works proposed polynomial-time algorithms to the flock pattern problem with fixed time duration. This master thesis proposes a new online method, called PSI, which is an improved base method to discover flock patterns that applies the plane sweeping computational geometry technique along with binary signatures and inverted indexes. In addition to PSI,thiswork proposes an algorithm family also based in the baseline algorithm proposed in literature, namely BFE, as well as variations based in heuristics. All the methods proposed in the work were extensively evaluated using real and synthetic datasets and the obtained results show that the techniques proposed in this work generate high performance gains when applied to the problem of finding flock patterns. Lastly, in order to better understand the results and to indicate a the best and worse scenarios for the utilization of the techniques this work also includes a profound analysis of the relationship between results and data distribution, and other data characteristics.
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Vávra, Jakub. „Šifrování telefonních hovorů“. Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2008. http://www.nusl.cz/ntk/nusl-235954.
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This master's thesis is about making draft and implementing land-line phone call encryption using FITkit. The ultimate goal is to find suitable compression and encryption methods, implement or adapt them for FITkit board and create functional solution.